Academic literature on the topic 'Pinus patula – Mechanical properties'

Wood density, latewood percentage, ring width and the cross sectional dimensions of tracheids (wall thickness, lumen area, radial and tangential lumen diameters) were evaluated from ten-year-old trees of Pinus maximinoi H.E. Moore, P. pseudostrobus Lindley and P. patula Schiede ' Deppe grown in South Africa. The species were almost equal in terms of average volume per tree. The wood of P. patula differed from the other species in latewood percentage, tracheid wall thickness, lumen area, radial and tangential lumen diameters. Apart from ring widths, significant differences within species were found for all of the wood and tracheid properties studied. The wood of P. patula has a higher latewood percentage especially in the outer parts of the stem and smaller tracheids than the other two species. The wood densities of P. patula and P. maximinoi were similar. The tracheids of P. pseudostrobus had thinner cell walls than the other two species and wood density was also lower for this species possibly as a result of reduced volume of cell wall material. The differences between and within species for wood and tracheid properties suggest that end use products will vary according to the seed source used.

Abstract The visible and near infrared (NIR) (500–2400 nm) spectra and mechanical properties of almost 1000 small clearwood samples from six softwood species: Pinus taeda L. (loblolly pine), Pinus palustris, Mill. (longleaf pine), Pinus elliottii Engelm. (slash pine), Pinus echinata Mill. (shortleaf pine), Pinus ponderosa Dougl. ex Laws (ponderosa pine), and Pseudotsuga menziesii (Mirb.) Franco (Douglas fir) were measured. Projection to Latent Structures (PLS) modeling showed that the NIR spectra of these softwoods could be used to predict the mechanical properties of the clear-wood samples. The correlation coefficients for most of these models were greater than 0.80. All six softwood species were combined into one data set and a PLS model was constructed that effectively predicted the strength properties of any of the individual softwoods. Reducing the spectral range to between 650 and 1050 nm only causes a slight decrease in the quality of the models. Using this narrow spectral range enables the use of smaller, faster, lighter, less expensive spectrometers that could be used either in the field or for process control applications.

The objective of this research was to evaluate the physical and mechanical properties of briquettes produced with charcoal fines and waste of Pinus spp (sawdust and wood shavings). For the production, the charcoal fines of two particle sizes (less than and greater than 5 mm) were mixed with each type of wood waste of Pinus spp in the proportions of 5, 10, 15, and 20%. Then, the mixtures were compacted under the pressure of 55 kgf.cm-2 in a piston briquetter. As binder, 8% gelatinized maize starch was used. Tests were carried out on the briquettes in order to determine the apparent density, compressive strength, and friability index. Briquettes with the highest densities and compressive strengths were produced with the two lowest proportions of wood waste of Pinus spp (5 and 10%). The use of the charcoal fines combined with sawdust or wood shavings of Pinus spp is recommended for the production of briquettes with good physical and mechanical properties.

Pinus halepensis Mill. was introduced into regions with a Mediterranean cli- mate as an ornamental tree, and is now often found in parks and gardens. At pre- sent, Aleppo pine (Pinus halepensis Mill.) forests cover approximately 2,500,000 ha in the Mediterranean Basin, mostly at low altitudes (less than 500 m) and along the coast. It has become naturalized outside cities in North Africa to the extent that it is now listed as an invasive species there. Because of its size (over 15 m in height and 30 cm in diameter), Pinus hale- pensis could be a good potential green resource for structural material in Tunisia. The focus of this study was to assess rot resistance and the physical and mecha- nical properties of reforestation Aleppo pine from the Mediterranean basin. The Pinus halepensis wood samples studied were collected from 6 tree provenances in Tunisia for physical and mechanical characterization and from Morocco for decay and termite resistance tests. Den- sities and shrinkage were determined and mechanical and rot resistance tests performed. Preliminary results showed that Tunisian Pinus halepensis wood has great dimensional stability. Although the compressive strength of Pinus halepen- sis wood is high, its bending strength is rather low for each of the provenances. MOR in bending is lower than in other Tunisian softwood species. Finally, Pinus halepensis sapwood has low resistance to fungi and termites. This timber species could be valuable for furniture and/or as a building material provided that a wood preservation method is applied before it is used.

Thesis (MScFor (Dept. of Forest and Wood Science)--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: In this study 1345 pieces of 38x114 mm timber sawn from 16-20 year-old Pinus patula trees were obtained from a wide variety of sites along the Mpumalanga escarpment in South Africa. The samples were tested for various mechanical and physical properties. The objectives of this study were (1) to determine the variation in the bending strength, tension strength, and stiffness of the sawn timber, (2) to assess the efficiency of the current visual and mechanical grading rules on this sample, and (3) to evaluate the potential of some indicator properties to be used as structural grading parameters on this resource. A large number of non-destructive measurements were performed on all the samples, including scanning of the boards with a commercial X-ray density scanner, moisture content measurement, growth ring measurements, warp measurement, acoustic frequency measurement and measurement of the stiffness using a mechanical grader. The data from the X-ray density scanner was used to calculate a number of knot-related variables for each board. Visual grading according to the SANS 1783-2 (2005) specifications for structural timber was performed by a certified grader on all the boards. The timber was divided into two groups for destructive testing, one group each for bending and tension tests. Tests were conducted according to the SANS 6122 (1994) method for in-grade testing. Due to the sampling method followed, the destructive tests effectively used a random placement of defects with regard to the load application position. From the destructive tests the modulus of elasticity (MOEedge), bending strength (MOR) and tensile strength were determined. The study showed that the MOEedge of the sawn timber was far below the requirements of the current national standard (SANS 10163-1) for all of the visual and mechanical grades. The mean MOEedge of the visually graded S5 timber was about 30% lower than required. The 5th percentile values for bending strength of all the visual and mechanical grades were above the required values of SANS 10163-1. The 5th percentile values for tensile strength of all the visual and mechanical grades were similar to that required by the SANS 10163-1 standard. Correlations between flatwise measured MOE (MOEflat) and edgewise measured MOE (MOEedge) were smaller than expected, as well as the correlations between both MOEedge and MOEflat with MOR. Dynamic MOE (MOEdyn), calculated from acoustic frequency tests on the timber, was found to be the best single predictor of MOEedge, MOR and tension strength. Multiple regression analysis showed that a combination of MOEdyn, density and knot parameters can be used to improve the predictability of some of the strength and stiffness characteristics of the timber. It is recommended that a comprehensive study on the structural grading of SA Pine be performed which includes (1) an analysis of market requirements in terms of strength and stiffness properties of timber, (2) in-grade testing of a representative sample of structural timber in South Africa, and (3) a review of the standards used in South Africa to regulate the structural grading of timber.
AFRIKAANSE OPSOMMING: In hierdie studie is 1345 stukke 38x114 mm 16-20 jaar-oue Pinus patula planke, afkomstig van ‘n wye verskydenheid groeiplekke teen die Mpumalanga platorand in Suid Afrika, gebruik. Die planke is getoets vir verskeie meganiese sowel as fisiese eienskappe. Die doelwitte van hierdie studie was om (1) die variasie in buigsterkte, treksterkte en styfheid van die gesaagde planke te bepaal, (2) die effektiwiteit van die huidige visuele -en meganiese graderingsreëls op hierdie monster planke vas te stel, en (3) die potensiaal te evalueer van sommige eienskappe wat gebruik kan word as strukturele graderingsparameters. ‘n Groot hoeveelheid nie-destruktiewe toetse is op alle planke uitgevoer, wat ingesluit het skandering van planke met ‘n kommersiële X-straaldigt-heidskandeerder, metings van voginhoud, groeiringwydtes, deformasie, akoestiese frekwensie en die bepaling van styfheid met behulp van ‘n meganiese gradeerder. Die data van die X-straalskandeerder is gebruik om ‘n aantal kwasverwante veranderlikes vir elke plank te bereken. Visuele gradering is op alle planke uitgevoer ooreenkomstig met die SANS 1783-2 (2005) spesifikasies vir strukturele hout deur ‘n gesertifiseerde gradeerder. Die hout is in twee groepe opgedeel vir destruktiewe toetse, een vir buigtoetse en een vir trektoetse, ooreenkomstig met die SANS 6122 (1994) metode vir binnegraadse toetse. As gevolg van die monsternemingsmetodiek wat gevolg is, is daar effektief gebruik gemaak van ‘n lukrake plasing van defekte met betrekking tot die las-aanwendingsposisie. Die modulus van elastisiteit (MOEedge), buigsterkte (MOR) en treksterkte is deur middel van destruktiewe toetsresultate bepaal. Die studie het aangetoon dat die MOEedge van gesaagde hout aansienlik minder as die vereiste van die huidige nasionale standaard (SANS 10163-1) is vir al die visuele en meganiese grade. Die gemiddelde MOEedge van die visueel-gegradeerde S5 planke was omtrent 30% laer as vereis. Die 5de persentiel waardes vir buigsterkte van alle visuele en meganiese grade was hoër as die vereiste waardes soos voorgeskryf deur SANS 10163-1. Die 5de persentiel waardes vir treksterkte van alle visuele en meganiese grade was gelykstaande aan wat vereis word deur SANS 10163-1. Korrelasies tussen MOE, gemeet op die wydte sy (MOEflat), en MOE, gemeet op die diktesy (MOEedge), asook die korrelasies van beide MOEedge en MOEflat met MOR van die planke was laer as verwag. Dinamiese MOE (MOEdyn), wat bereken was vanaf die akoestiese frekwensie resultate, is vasgestel as die beste enkele indikator van MOEedge, MOR en treksterkte. Meervuldige regressie analise het aangetoon dat ‘n kombinasie van MOEdyn, digtheid en kwasparameters gebruik kan word om die voorspelbaarheid van sommige van die sterkte- en styfheids eienskappe van die hout te verbeter. Daar word aanbeveel dat ‘n omvattende studie gedoen word op die strukturele gradering van SA Dennehout, wat insluit (1) ‘n analise van die markbehoeftes in terme van die sterkte- en styfheids eienskappe van hout, (2) binnegraadse toetsing van ‘n verteenwoordigende monster strukturele hout in Suid Afrika, en (3) die hersiening van standaarde in gebruik in Suid Afrika om die strukturele gradering van hout te reguleer.

The study of a methodology to model the mechanical properties of Pinus Radiata takes place from the nanoscopic cell fiber [3] to the board scale level. Gibson and Ashy had generalized wood cells into hexagonal cells, previous work [2] extends the model specifically for Pinus Radiata. Unfortunately, earlier work was done on published data from various sources, not necessary related to Pinus Radiata nor from a common reference piece of characterized Pinus Radiata, making correlation with experimental work [4] difficult. Further work was done by the author on a characterized sample of Pinus Radiata to correlate elastic properties with actual cellular geometry and experimental result. Critical geometrical parameters were studied for a feasible mathematical idealization as necessary parameters to further refine the FEM model. Two approaches were used in evaluating board scale modeling; actual wood cells geometry and idealized hexagonal models. These models are extended to Growth ring model to predict growth ring mechanical properties and validated with experimental results as a preliminary Board scale model. Stol had modeled Wood cells as hexagonal cellular material using Gibson's [1] analytical solution in his work with orthotropic wood wall's properties [2]. Sto1's analytical solution neglects the longitudinal dimension, which in realism is closer to plate than beam. Gibson and Asbhy's work on prediction of cellular properties analytically formed the basis of formulation analytical solution using energy method (Ritz's method) with plate type stiffness function and further extended with shear and longitudinal boundary coupling effect. The plate analytical solution was validated by FEM to be in close agreement, within a 5% error. The model based on real cell geometry and its equivalent regular array of identical cell has broad agreements with experimental values. Further refinements of this model are important steps in the development of a definitive model. Preliminary work on a growth ring FEM model is important as part of the preparation for a board scale model, however further refinements would be necessary for definitive board scale FEM model.

Thesis (PhD(For))--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Pinus patula is the most intensively planted conifer in the tropics and sub‐tropics. In South Africa Pinus patula plantations are the main saw‐log resource for structural lumber production. Improved intensive silvicultural practices and tree breeding have resulted in marked increases in the rate of growth. To reap the financial benefits of the faster growth, plantation managers are more and more inclined to reduce rotation ages, which inevitably results in the production of higher proportions of juvenile wood at final harvest, and lumber which often does not meet the minimum requirements for stiffness for structural lumber. Knowledge of the variation and the accurate prediction of the mechanical properties of the timber of standing trees can have various benefits for growers and processors of trees. It can be used for tree allocation to different processing facilities, for processing production planning, and to assist tree breeders to screen and select for superior breeding material. The objectives of this study were (1), to examine the within‐ and between‐tree variation in wood properties of young South African grown Pinus patula trees known to have important impacts on the suitability of sawn lumber for structural purposes and (2), to develop empirical prediction models for the flexural lumber properties from standing Pinus patula, based on variables that could be assessed non‐destructively from standing trees. Sample material was obtained from 170 trees (16‐20 years old) established in 17 compartments along the Mpumalanga escarpment of South Africa. A large number of variables which could be obtained non‐destructively from the trees while they were still standing, were measured. The trees were subsequently felled and two logs, 2.1 m in length, were extracted from each tree at two height positions. The 340 logs were processed into 1402 pieces of lumber for further measurements and destructive testing. Results showed that the mean modulus of elasticity measured on edge (MOEedge) was far below the limits set for structural grade softwood timber in South Africa. All the desirable properties for structural lumber improved with distance from the pith with the exception of the 5th percentile value for modulus of rupture (MOR), which was higher at the pith than for the boards processed adjacent to the pith. Boards processed from the lower part of the stem were superior in most of the important properties compared to those higher up in the stem. Separate multiple regression models for predicting the average dynamic MOE (MOEdyn) of individual boards, trees and compartments were developed. The models managed to explain 68%, 60% and 95% of the variation in MOEdyn respectively. The models developed for MOR explained 40% and 42% of variability at board and tree level respectively. At compartment level, 80% of the variation in the 5th percentile MOR value could be explained by the model. Sensitivity analyses showed that site index at base age of 10 years, acoustic time‐of‐flight, wood density and ring width were the most influential variables in the MOE models. The models indicated that tree slenderness during early growth seems to play a major role in determining the dynamic MOE and MOR of lumber. This is in agreement with Euler’s buckling theory and the bending stress theory. Microfibril angle (MFA) and density were measured on radial strips taken from a sub‐sample of trees with the Silviscan 3 technology. The mean microfibril angle per year ring in Pinus patula varied between 7o and 29o. In general MFA decreased with distance from the pith and height above ground level. A multiple regression model including microfibril angle, density and ring width explained 71% of the variation in the dynamic MOE of boards. Sensitivity analysis on the model showed that microfibril angle and density had roughly equal influences on predicting the MOEdyn of Pinus patula boards.
AFRIKAANSE OPSOMMING: Pinus patula is die mees aangeplante naaldhoutspesie in die tropiese en sub‐tropiese areas van die wêreld. Dit is die grootste bron van saagblokke vir die produksie van strukturele hout in SA. Intensiewe boskultuurpraktyke en boomteling het gelei tot ‘n merkbare verhoging in die groeitempo van die spesie. Plantasiebestuurders is gevolglik geneig om rotasie‐ouderdomme te verlaag, wat lei tot ‘n groter persentasie jeughout wat nie aan die minimum styfheidvereistes van strukturele hout voldoen nie. Kennis van die variasie en die akkurate voorspelling van die meganiese eienskappe van staande bome kan voordele inhou vir beide die verbouers en verwerkers van bome. Dit kan byvoorbeeld van hulp wees met die toewysing van bome aan verwerkingsfasiliteite, vir produksiebeplanning, en vir ondersteuning met die keuse van teelmateriaal vir boomtelers. Die doelwitte van hierdie studie was (1), om die binne– en tussenboomvariasie in die houteienskappe, wat ‘n bepalende invloed het op die geskiktheid van jong Suid Afrikaanse Pinus patula bome vir strukturele hout produksie, te ondersoek en (2), om empiriese modelle vir die voorspelling van die buigeienskappe van planke te ontwikkel, gebaseer op veranderlikes wat niedestruktief op staande Pinus patula bome ge‐evalueer is. Monsters vir die studie is verkry vanaf 170 bome (16‐20 jaar oud), geplant in 17 vakke op die Mpumalanga platorand van Suid Afrika. ‘n Groot aantal veranderlikes is nie‐destruktief gemeet op die staande bome waarna die bome gevel is en twee saagblokke, 2.1m in lengte, is op twee hoogte posisies uit elke boom verwyder. Die 340 blokke is verwerk tot 1402 planke vir verdere metings en destruktiewe toetse. Resultate het getoon dat die gemiddelde modulus van elastisiteit gemeet op die dwarskant (MOEedge) aansienlik laer was as wat vereis word vir strukturelegraad hout in Suid Afrika. Al die gewenste eienskappe het toegeneem met afstand vanaf die murg behalwe die 5de persentiel breekmodulus (MOR), wat hoër was vir murgplanke as vir aangrensende planke. Planke afkomstig van die laer dele van die stam het oor die algemeen beter eienskappe gehad as planke afkomstig van die hoër dele. Veelvuldige regressiemodelle kon 68%, 60% en 95% van die variasie in die gemiddelde dinamiese MOE (MOEdyn) op die vlak van onderskeidelik individuele planke, bome en vakke verklaar. Die modelle vir MOR kon 40% en 42% van die variasie op onderskeidelik plank‐ en boomvlak verklaar. Die model vir 5de persentiel MOR van vakke kon 80% van die variasie verklaar. ‘n Sensitiwiteitsanalise het aangetoon dat groeiplekindeks op ouderdom 10, akoestiese vlugtyd, digtheid en jaarringwydte die belangrikste veranderlikes was wat MOEdyn beïnvloed het. Die modelle het aangetoon dat die slankheid van bome tydens vroeë groei vermoedelik ‘n belangrike invloed op die MOEdyn en MOR van planke het. Dit is in ooreenstemming met Euler se knikteorie en die buigsterkteteorie. Die mikrofibrilhoek en digtheid van ‘n steekproef van die bome is gemeet met die Silviscan 3 apparaat. Die gemiddelde mikrofibrilhoek per jaarring het tussen 7 o en 29o varieer. Hierdie variasie was hoofsaaklik afhanklik van boomhoogte en aantal jaarringe vanaf die murg. ‘n Veelvuldige regressiemodel wat mikrofibrilhoek, digtheid en jaarringwydte insluit, kon 71% van die variasie in MOEdyn verklaar. ‘n Sensitiwiteitsanalise op die model het aangetoon dat mikrofibrilhoek en digtheid ongeveer ewe belangrik was wat betref hulle invloed op die voorspelde MOEdyn van Pinus patula planke.

The objectives of this study were to study wood property variation in Pinus patula from different physiographic sites, the interrelationship between wood properties and the effects of some forest site factors on wood properties and their within-tree variation. The wood properties considered were density, transverse shrinkage, grain angle and stiffness (modulus of elasticity). Ten trees were taken from each of seventeen sites selected during a previous study of soil ecology and tree growth patterns on the escarpment of Mpumalanga in South Africa. This is a complex physiographic region with several different growth sites within a relatively small geographical area. The key finding of the study was that the effect of radial distance from the pith (i.e. the age of the tree) was highly significant and accounted for most of the variation of the trees sampled. Although the effect of site on the selected wood properties was highly significant, its effect accounted for a relatively small percentage of the total variation in each case. Consequently, solid wood processors must take into account the large variation within a tree when implementing strategies to minimise the downgrade of timber as result of excessive board distortion and/or inferior strength. There were significant correlations between wood density and density slope, radial shrinkage, shrinkage ratio and stiffness and also significant correlations between wood stiffness and density slope and radial shrinkage. Density and grain angle both showed significant correlations with the most important climatic factors. ‘Growth days’ (which is an index reflecting the number of days per year when soil moisture is not a limiting factor for plant growth) was identified as one of the principal growth factors influencing the selected wood properties, because of it’s strong relationships with wood density, density slope, grain angle and stiffness. Regression models were developed to predict wood density and grain angle from growth variables. The results show that those wood properties that correlate with geographic representable site variables can be included in site classification and evaluation systems, to assist in predicting growth in terms of volume yield and wood quality.

A possibilidade de utilização da técnica de colorimetria para obter informações relevantes das peças de Pinus é uma excelente alternativa, uma vez que o colorímetro é um equipamento de fácil manuseio e rápida aquisição de dados, e o uso de madeira de florestas plantadas é crescente no Brasil. O objetivo desta pesquisa foi gerar modelos de regressão para estimativa da densidade aparente e das propriedades mecânicas (resistência e módulo de elasticidade) em função de parâmetros colorimétricos. Nesta pesquisa, 403 amostras de Pinus sp. foram caracterizadas de acordo com o sistema CIE L*a*b*, utilizando um colorímetro Konica Minolta. A densidade aparente, a resistência à compressão paralela às fibras e o módulo de elasticidade na compressão paralela às fibras das 403 amostras também foram determinados, de acordo com as premissas do Anexo B da norma brasileira ABNT NBR 7190 (1997). Foi proposto um modelo de regressão multivariável e testado utilizando análise de variância (ANOVA), ao nível de significância de 5%, para estimar as três propriedades citadas, em função dos parâmetros colorimétricos e do número anéis de crescimento (quantidades de lenho inicial e lenho tardio). Os resultados indicaram que a madeira apresenta coloração branco-amarelada, pois possui valor de luminosidade (L*) superior a 54. A pigmentação amarela (b*) é a principal responsável pela formação das cores no gênero Pinus. A análise de correlação entre cor, número de lenhos (Nle) e densidade revelou que apenas a luminosidade, o número de lenhos e a interação desses fatores afetaram significativamente os valores de densidade. A diminuição da luminosidade e o aumento na quantidade de lenhos implicam um aumento significativo nos valores de densidade da madeira. A análise de correlação entre cor, número de lenhos e módulo de elasticidade revelou que apenas o número de lenhos afetou significativamente os valores do módulo de elasticidade. O aumento no número lenhos implica aumento significativo no módulo de elasticidade na compressão paralela às fibras. A análise de correlação entre cor, número de lenhos e resistência à compressão paralela às fibras mostrou que apenas os fatores L*, a*, b* e as interações L*·b*, a*·b*, afetaram significativamente os valores da resistência. A interação entre os fatores L* e b* implicou na redução dos valores da resistência à compressão paralela às fibras. A técnica de colorimetria mostrou-se adequada para a estimativa de propriedades físico-mecânicas da madeira.
The possibility of using the colorimetric technique to obtain relevant information of Pinus pieces is an excellent alternative, since the colorimeter is an equipment of easy handling and quick data acquisition, and the use of wood from planted forests is growing in Brazil. This research aims to generate regression models to estimate the wood density and mechanical properties (strength and modulus of elasticity) as a function of colorimetric parameters. Here, 403 pieces of Pinus sp. have been characterized according to the CIE L*a*b* system using a Konica Minolta colorimeter. The apparent density, the compression parallel to the grain strength and the modulus of elasticity in the compression parallel to the grain of the 403 samples were also determined, according to the assumptions of Brazilian standard code ABNT NBR 7190 (1997). It was proposed a multivariate regression model and tested using analysis of variance (ANOVA), at 5% significance level, to estimate the density, the compressive strength and the modulus of elasticity as a function of the colorimetric parameters and the number of tree growth rings (earlywood and latewood). Results indicated that the wood has a yellowish-white coloration, with a value of brightness (L*) higher than 54. The yellow pigmentation (b*) is the main responsible for the color formation of the genus Pinus. Correlation analysis among color, number of tree growth rings (Nle) and density showed that only the brightness, the number of tree growth rings and the interaction of these factors affected significantly the values of density. Decreasing in brightness and increasing in the number tree growth rings implies a significant increasing in wood density values. Correlation analysis among color, number of tree growth rings and modulus of elasticity showed that only the number of tree growth rings affected significantly the values of modulus of elasticity. Increasing in the number tree growth rings implies a significant increasing in the modulus of elasticity. Correlation analysis among color, number of tree growth rings and compression parallel to the grain strength showed that only the factors L*, a*, b* and the interactions L* ·b*, a*· b*, affected significantly the values of strength. The interaction between the factors L* and b* implied the reduction of the values of the compression parallel to the grain strength. The colorimetric technique was appropriated for estimative of physico-mechanical properties of wood.

O setor da construção civil é um dos que mais consomem recursos naturais e utilizam energia de forma intensiva, gerando consideráveis impactos ambientais juntamente com grande quantidade de resíduos. A utilização de produtos alternativos como painéis de madeira surge como uma possibilidade de redução de tais impactos. O Oriented Strand Board, desenvolvido para substituir o painel compensado, tem conquistado cada vez mais espaço na construção apesar de sua menor estabilidade dimensional perante o seu antecessor. A adição de resíduos, como o plástico, na matriz constituinte destes painéis representa alternativa de reaproveitamento destes descartes e economia de madeira no processo produtivo destes compósitos, além de proporcionar melhoria nas propriedades físicas dos mesmos. O objetivo deste trabalho foi confirmar a viabilidade técnica da produção de painéis OSB de madeira de Pinus sp. com adição de proporções de 20 e 30% de partículas de polipropileno biorientado em sua matriz constituinte e resina poliuretana à base de óleo de mamona. A avaliação de desempenho foi feita por intermédio das propriedades físicas e mecânicas dos painéis, determinadas atendendo as recomendações da EN 300 (1999). Os painéis foram classificados como OSB 4, de acordo com as propriedades físicas avaliadas, e OSB 1, considerando os módulos de elasticidade e ruptura obtidos em ensaios de flexão estática. A adesão interna, para os painéis produzidos com os parâmetros de processo adotados, não alcançou os valores exigidos pela citada norma. De todas as propriedades avaliadas, apenas inchamento em espessura e absorção de água foram influenciadas pela porcentagem de BOPP. Assim, considera-se comprovada a viabilidade técnica da produção dos painéis OSB deste trabalho, para aplicação na construção civil.
Building construction is one of the sectors that most consuming natural resources and use energy intensively, generating considerable environmental impacts coupled with large amount of waste. Employing alternative product like wood panels comes as a possibility to reduce these impacts. Oriented Strand Board, developed to substitute the plywood panel, has gained more space in the construction spite of its lower dimensional stability against its predecessor. The addition of plastic waste in constitutive matrix of these panels represents an alternative to reuse this kind of waste and wood economy in the productive process of these composites, besides improving their physical properties. The aim of this study was to evaluate the technical feasibility of producing OSB of Pinus sp. wood with the addition of various proportions of particles of bioriented polypropylene in its constitutive matrix and polyurethane resin based on castor oil with evaluation of physical and mechanical properties of these panels. In accordance with EN 300 (1999), the OSB panels have been classified as 4 in accordance with the physical properties assessed and as OSB 1 for the elasticity modules and rupture. Property of internal bond not presented the minimum values required by the same standard. Of all properties evaluated, only thickness swelling and water absorption were influenced by the percentage of BOPP. However, it is considered completely evidenced the technical viability of production of the OSB of this work, and its potential employability in civil construction sector.

O presente trabalho teve como objetivo avaliar o potencial de utilização da madeira do híbrido Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis para a produção de lâminas e manufatura de painéis compensados. Para realização do estudo foram utilizadas 10 toras de 1,30 m de comprimento, provenientes de 5 árvores coletadas aos 7 anos e 10 meses de idade nos plantios da empresa Pinus Brasil, localizada em Buri - SP. O rendimento do processo de laminação das toras e a qualidade das lâminas produzidas foram avaliados. O delineamento para a produção experimental e avaliação dos painéis compensados constituiu-se de 8 tratamentos arranjados em esquema fatorial, através dos quais foram analisados os efeitos de duas posições de retirada da tora no tronco (A e B), duas gramaturas de adesivo (380 e 420g/m²) e dois tempos de prensagem (8 e 12 minutos). Para cada tratamento foram produzidos 3 painéis compensados, cada qual com 5 lâminas coladas entre si com adesivo à base de fenol-formaldeído. O rendimento médio do processo de laminação das toras, sem casca, foi de aproximadamente 53%, podendo ser considerado bom e compatível com outros resultados encontrados na literatura. As toras A, mais próximas da base das árvores, produziram maior número de lâminas, no entanto, de qualidade inferior em relação às lâminas das toras (B). A massa específica aparente dos painéis estudados foi relativamente baixa em comparação a outros compensados de Pinus, cuja propriedade apresentou valor médio estatisticamente superior para os compensados confeccionados com lâminas das toras A. Os painéis apresentaram boa estabilidade dimensional, sendo que o tempo de prensagem de 12 minutos para a produção dos compensados resultou em diminuição estatisticamente significativa do inchamento em espessura. O tempo de prensagem, gramatura de adesivo e posição da tora influenciaram os valores de resistência da colagem dos painéis, sendo que os maiores valores foram observados para os painéis produzidos com lâminas das toras B, tempo de prensagem de 12 minutos e gramatura de 420g/m². Os valores médios do módulo de ruptura (MOR) e do módulo de elasticidade (MOE) à flexão estática dos painéis foram, respectivamente, compatíveis e inferiores quando comparados com os do Catálogo Técnico n°1 Compensados de Pinus (ABIMCI, 2002). Houve efeito do fator posição da tora no MOR paralelo dos painéis e o maior valor médio foi observado para os compensados confeccionados com lâminas das toras da posição A. Houve interação entre os fatores posição da tora e tempo de prensagem para o MOR e MOE perpendiculares, sendo que, de modo geral, os menores valores foram observados para os compensados confeccionados com lâminas das toras B e prensados no tempo de 12 minutos. Conclui-se que a madeira do híbrido estudado apresenta bom potencial para a produção de lâminas e manufatura de compensados. Porém, o emprego desses painéis em produtos que requeiram elevados valores do MOR e do MOE, por exemplo, em formas de concreto, não é aconselhável, porque esses painéis não satisfariam tais requisitos.
The main objective of this work was to evaluate the potential of wood utilization from Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis hybrid for veneer production and plywood manufacturing. This study used 10 logs measuring 1.30m in length, obtained from 05 trees, 07 years and 10 months of age, from plantations located in Buri SP, Brazil. Peeling process yield and quality of veneers produced were evaluated. The experimental design consisted of eight treatments, arranged in a factorial way, being the effects of two log positions (A and B) on the trunk, two adhesive spread rates (380 and 420g/m²) and two press times (8 and 12 minutes). Three plywood panels were produced for each treatment and each panel was constituted of 05 veneers glued with an adhesive based on phenol-formaldehyde. The peeling process yield was approximately 53%, based on logs without bark, and can be considered good and compatible with other results found in the literature. The logs A, closer to the base of the tree, produced a greater number of veneers, but of inferior quality compared to the logs B veneers. The apparent specific mass of the plywood panels was relatively low, compared to other Pines plywood available in the literature, with a superior mean value for the plywood made with veneers of logs A comparing to logs B. The plywood panels showed good dimensional stability. The press time of 12 minutes resulted in significant thickness swelling decrease and the press time, adhesive spread rate and log position, influenced the bonding line strength. The best results of bonding line strength were obtained for the plywood produced with logs B veneers, press time of 12 minutes and spread rate of 420g/m². The static bending properties of the plywood panels studied, modulus of rupture (MOR) and modulus of elasticity (MOE),were compatible and inferior, respectively, compared to other Brazilian-pines plywood. There was an effect of the log position factor on the MOR-parallel-to-grain with best results obtained for plywood panels produced with veneers of logs A. There was interaction between the log position and press time factors on the MOR and MOE, both perpendicular-to-grain, with the lowest values observed for plywood panels produced with log B veneers and press time of 12 minutes. The hybrid pine wood studied has good potential for veneer production and plywood manufacturing. However, the use of these panels in products that require high values of MOR and MOE, for example, in formwork is not advisable, because these panels do not satisfy these requirements.